PHILADELPHIA – Omar Gonzalez had just left the LA Galaxy to join Mexico's Pachuca when his new club's chairman had a request: Would the 6-foot-5 defender walk into his introductory news conference dressed as Darth Vader?Of course, he obliged. Ever since, he has become a defensive force."I had signed a contract 15 minutes prior to that, so I was like, 'Yeah, sure.' It was a bit small," Gonzalez recalled of the costume Tuesday. "I don't know if they met any other Mexican my size."Now 28 years old, Gonzalez is among the U.S. players trying to impress returning coach Bruce Arena in the CONCACAF Gold Cup. The Americans play El Salvador on Wednesday night in a quarterfinal match.He made his national team debut in August 2010 during an exhibition against Brazil, which gave a teenage forward named Neymar his first international appearance that night in New Jersey.Gonzalez went on to become among Major League Soccer's highest-paid players, but his career stalled: first a torn knee ligament during his initial training session following a January 2012 loan to the German club Nuremberg, then a knee injury that kept him from starting the first two games of the 2014 World Cup.But worst of all was malaise during his final seasons with the Galaxy."I was just doing enough to get by and things were OK," he said.Gonzalez decided to change his attitude and alter his rest regimen. He signed with Pachuca in December 2015, helped that team win last year's Clausura title — and now he is flourishing on a team that will be in this year's Club World Cup."Everyone said this is the next so-and-so. And that's all well and good, but until you get out there and prove it," U.S. goalkeeper Tim Howard explained."He's matured. When you have ability and other people think you have ability, it's great. When you actually realize your own ability and potential, I think the game slows down for you a little bit and you get very comfortable with your own movements and your own communication."Born in Dallas to Mexican-American parents, Gonzalez could have played for either country. An All-American at Maryland, he was the third pick overall in the 2009 MLS draft and then that season was voted MLS Rookie of the Year with the Galaxy, all while being coached by Arena.During the defender's time in LA., Gonzalez met Erica, the woman he would marry, at the 30th birthday party of Kenny Arena, now as assistant coach for his dad.Gonzalez lived in Manhattan Beach but decided to shake up his life with the move to Pachuca, a city of about 265,000, where he now lives with Erica and their two daughters, 2½-year-old Isla and 1-year-old Colette."It's just a totally different lifestyle," he said. "In LA, you're done with training and you sit around and you think, what should I do today? There's always something, to do, and Pachuca there's not really much to do."The family makes the hour-long drive to Costco outside Mexico City to fill the SUV with groceries and supplies. He is careful to check the calendar to avoid shopping on the middle and final days of each month."You don't go to the mall when it's pay day. When people get paid, it's packed," he said.He is convinced he would not have revived his career had he not decided to leave Los Angeles."It's definitely made me a better player and also made me a better person, living in a different culture, living in a different country, living in an environment you're not used to," Gonzalez said."I spent my whole career in LA before I made this move, under the same coach, and so things were very comfortable for me, I would say. And what Mexico did was put me in an uncomfortable position, and I went to a place where I was unsure of myself playing every single game, and Mexico I believe is still ahead of MLS in terms of the quality and the players' technical ability."Back with the national team, Gonzalez is competing for what likely will be four center back spots on the U.S. World Cup roster, assuming the Americans qualify.John Brooks and Geoff Cameron top the depth chart at the moment, with Gonzalez, Matt Besler, Matt Miazga and Matt Hedges the four splitting time at the Gold Cup. Gonzalez put the U.S. ahead in last week's 2-0 win over Martinique with his second goal in 42 international appearances."Moving to Pachuca has allowed him to focus a little bit more on his craft. I don't think he has the distractions he might have had in Los Angeles," Arena said,Gonzalez's teammates have noticed his strides."Your way of dealing with quick, skillful attacking players is put to the test every week," captain Michael Bradley said. "It's a guy who continues to show that he has to play a role for us moving forward."